@ Tim-1963 "Now, I don't know for certain if they are married."

Maybe his "wife" is a widow who will lose workers compensation or other benefits if she remarries.  I have had several clients in that situation.  Or maybe her spousal maintenance ends when she remarries.  There is no central registry of marriages and divorces in the United States, so it's not easy for anyone, including IRS, to know the facts.  Let's not get hurt, jumping to conclusions.  Thirty years in government can shelter you from the real-world soap opera that tax practitioners experience daily.

Earlier this year, a Tax Court litigant was not successful in his claim that he is married.  His social media footprints did him in.  See

https://procedurallytaxing.com/oversharing-on-social-media-reaches-the-tax-court/